Regular Expressions 101

^start of line

Group nthBase(?<nthBase>[+-]?\d+)

Character Class[+-]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d+a digit, repeated at least once

Non-Capturing Group(?:\*?(?<series>n)(?<crementer>[+-]\d+)?)?

?repeats the group contents below at most once:

\*?optionally matches the literal * (42₁₀ / 52₈ / 2A₁₆)

Group series(?<series>n)

nthe literal n (110₁₀ / 156₈ / 6E₁₆) (case sensitive)

Group crementer(?<crementer>[+-]\d+)?

?repeats the group contents below at most once:

Character Class[+-]

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d+a digit, repeated at least once

$end of line

Global pattern flags

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(?<nthBase>[+-]?\d+)(?:\*?(?<series>n)(?<crementer>[+-]\d+)?)?$

New

2n+1
2n
444
-22
+4n
-5*n
-5*n-3
-5n+44
--5
++5
-
+
-6-1
62-1
62n-1